The present invention relates to a cleaning device for the Xerography machine, which includes a brush in contact with a photoreceptor and an auger for transporting toner scraped off with the brush in the axial direction.
This type of the cleaning device is disclosed in Published Unexamined Japanese Utility Model Application No. Hei. 1-75276. In this cleaning device, the brush is always in contact with the auger.
There is another conventional cleaning device in which a flicker bar is in contact with the brush. This cleaning device is constructed as shown in FIG. 1. A flicker bar b, shaped like a frame in cross section, is formed of a plastic mold. It includes a part brought into contact with a brush a. The flicker bar b is fastened to a cleaning housing c by means of screw means. When an auger d is deformed upward, it comes in contact with the frame part of the flicker bar b. With this contact, the auger d is prevented from being excessively deformed toward the brush a.
Another technique is disclosed in Published Unexamined Japanese Patent Application No. Hei. 3-153287. In this technique, a bias voltage is applied to the shaft of a conductive brush. Therefore, a bias voltage applying means is indispensably required. In this respect, the disclosed technique is disadvantageous in space and cost.
An additional technique is disclosed in Published Unexamined Japanese Utility Model Application No. Sho. 63-146874. In this technique, toner is removed through the contact with the cleaning brush. Accordingly, an additional space is required for the roller and the flicker. This technique is also disadvantageous in space and cost.
The advantageous fact that when the cleaning brush per se is charged properly (viz., at a proper polarity and at a proper quantity of charge), the cleaning performance is improved, and paper particles, discharge by-products, talc, etc. are effectively removed, is confirmed. The disadvantageous fact that an excessive discharge brings about picture quality degradation, and generation of radio wave noise, is also known.
In the first conventional cleaning device disclosed in Published Unexamined Japanese Utility Model Application No. Hei. 1-75276, the auger is constantly pressed against the outer circumference of the brush. Because of this, the auger is deformed toward the opposite side of the brush. The thus deformed auger forcibly rubs the cleaning housing, so that noisy sound is generated and the inner surface of the housing is scraped off. When the collector bottle is full of toner and a heavy load is applied to the auger, the auger possibly damages the brush.
In the second conventional cleaning device of the type in which a flicker bar is in contact with the brush, a great variation of the quantity of the nip of the brush a and the flicker bar b makes it difficult to gain a proper flicking effect. With a structure that the flicker bar b is fastened to the upper wall of the cleaning housing c by screw means, the flicker bar b does not constitute one of the strengthening members of the cleaning housing c. In other words, it cannot reinforce the cleaning housing c in any way.
The number of the parts required for earthing the brush and the flicker bar is reduced as small as possible.
To remove electrical noise generated from the brush and the flicker bar, these must be earthed. Earthing of the brush is difficult since the rotating shaft of the brush must be earthed.